JP4157921B2 - Power transmission control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power transmission control device in a mechanism for transmitting power via an electromagnetic clutch, and more particularly to a power transmission control device suitable for controlling an electromagnetic clutch for a compressor in a vehicle air conditioner.
[0002]
[Prior art]
An electromagnetic clutch is often used to control the mechanical connection between the power supply and the driven equipment. For example, an electromagnetic clutch is provided in order to control transmission of driving force from an engine as a power supply source to a compressor provided in a refrigerant circuit of a vehicle air conditioner as a driven device. Controls the mechanical connection between the compressor and the compressor. In this driving force transmission system, the magnitude of the transmission torque that transmits the engine driving force to the compressor must be greater than the compressor torque when the compressor is driven, so that the driving force is reliably transmitted to the compressor. . Here, the transmission torque of the single dry plate clutch used in the vehicle air conditioner is expressed by the following equation.
T = M ・ F ・ R
T: Transfer torque M: Friction coefficient F: Axial suction force R: Effective radius of friction surface
The electromagnetic clutch controls the axial attractive force in the above equation. Conventionally, since a constant suction force is generated such that the transmission torque is equal to or greater than the maximum compressor torque during driving, the clutch is always controlled with the same electric power.
[0004]
[Problems to be solved by the invention]
However, the conventional control as described above has the following problems.
When a variable capacity compressor capable of varying the discharge capacity is used, the compressor torque varies depending on the compressor capacity, as shown in FIG. Further, the compressor torque shows the largest value at the time of starting the compressor, but after that (for example, after a certain time Δt elapses), the value becomes smaller and stable. Furthermore, since the compressor torque changes depending on the vehicle speed, the outside air temperature, the amount of solar radiation, the control mode of the air conditioner, etc., the minimum required transmission torque also changes.
[0005]
For example, as shown in FIG. 2, the compressor power changes depending on the air conditioner control mode (A / Cmode) and the outside air temperature. DRY (dehumidification mode) and ECON (economy mode) in FIG. 2 indicate an air conditioner control mode when the evaporator outlet air temperature control shown in FIG. 3 is performed. In the economy mode (ECON), power saving is achieved compared to the dehumidification mode (DRY).
[0006]
However, in the conventional technique as described above, as shown in FIG. 4, when the outside air temperature is relatively low, only a relatively low transmission torque is required for both the dehumidifying mode and the economy mode as shown in FIG. Nevertheless, the clutch power was always controlled at the maximum value. In other words, the clutch power (transfer torque) is fixed to a constant value at the maximum value required in any situation, so in reality, there is excess energy except when the compressor starts at the maximum compressor capacity. It will be consumed. In particular, in a variable capacity compressor, since the time during which the clutch is engaged is longer than in a fixed capacity compressor, the loss of energy in clutch control is increased, which is a problem.
[0007]
Accordingly, an object of the present invention is to solve the above problem by calculating and controlling the required clutch power value according to a change in the compressor torque instead of a constant value for the power applied to the clutch. It is to reduce energy loss.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, a power transmission control device according to the present invention is a power transmission control device including an electromagnetic clutch that controls mechanical connection between a power supply source and a driven device, and a clutch power supply unit. The power supply source is an engine, the driven device is a compressor provided in a vehicle air conditioner, driving force recognition means for recognizing the driving force of the driven device or an amount correlated therewith, and adjusting the clutch power It has a clutch power adjusting means and a clutch power calculating means for calculating the clutch power necessary for transmitting power, and is calculated by the clutch power calculating means according to the driving force recognized by the driving force recognizing means at the time of power transmission. as will be have been the driving force, co when with adjusting the clutch power by the clutch power conditioning unit, the off-time of the electromagnetic clutch long Depending on the length of time that the electromagnetic clutch has been turned off, the clutch power at the time of starting the compressor is large and the clutch power at the time of starting the compressor is small when the electromagnetic clutch is off. The clutch electric power is adjusted .
[0010]
In particular, when applied to a vehicle air conditioner, the driving force recognizing means is composed of a thermal load recognizing means for recognizing a thermal load having a correlation with the driving torque of the compressor, and the heat load recognized by the heat load recognizing means. Accordingly, the clutch power can be adjusted by the clutch power adjusting means so that the driving force calculated by the clutch power calculating means can be obtained.
[0011]
When the compressor is composed of a variable capacity compressor, the heat load includes compressor capacity control signal information, engine or compressor speed or / and vehicle speed or / and outside temperature or / and inside temperature or / and inside / outside air intake. It can be estimated by referring to the air switching information and / or the voltage of the blower that blows into the passenger compartment or / and the voltage of the refrigerant cooling fan.
[0012]
In the present invention, the driving force recognition means can be configured as means for estimating from various state quantities as described above, but can also be configured as means for directly detecting the transmission torque by a torque sensor.
[0013]
In addition, as described above, immediately after the clutch voltage is turned on and the clutch is engaged, the electromagnetic clutch has the largest driving force of the driven device and the transmission torque to the driven device, and then a certain time has passed. Since the driving force and the transmission torque are later stabilized, it is preferable that the driving force is controlled regardless of the value of the driving force calculated by the clutch power calculating means while the driving force is rising immediately after the clutch is turned on. . For example, the maximum clutch voltage is set to the electromagnetic force during the time required for the driving force that has risen immediately after the clutch is turned on to be stable, or while the driving force recognized by the driving force recognition unit immediately after the clutch is turned on is a certain value or more. It is preferable to supply the clutch.
[0014]
The clutch power adjusting means may be configured as means for adjusting clutch power by adjusting the clutch voltage, or may be configured from means for adjusting clutch power by pulse width modulation control or duty control of clutch voltage on / off. You can also.
[0015]
When a compressor is used as in the present invention , generally, there is a correlation between the compressor stop time (clutch off time) and the starting torque, and the shorter the clutch off time, the smaller the compressor torque at starting. Therefore, when the electromagnetic clutch is off, the clutch power at the time of starting the compressor is large, and when the electromagnetic clutch is off, the clutch power at the time of starting the compressor is small. Adjust the clutch power when starting the compressor according to the length .
[0016]
Further, in the present invention, it is possible to add a configuration that includes slip detection means for detecting a difference in rotational speed between the power supply source and the driven device, and increases the clutch power during a slip.
[0017]
In the power transmission control device according to the present invention as described above, the power supplied to the electromagnetic clutch is not a constant value, but is controlled to the minimum power required for power transmission at that time or slightly higher power than that. As a result, energy can be saved significantly compared with the conventional constant value control.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
Each embodiment shown below demonstrates the case where the power transmission control apparatus of this invention is applied to control of the electromagnetic clutch of the variable capacity compressor provided in the refrigerant circuit in a vehicle air conditioner.
[0019]
FIG. 5 shows the power transmission control device according to the first embodiment of the present invention, and particularly shows clutch control when an external variable compressor is used in the vehicle air conditioner. In FIG. 5, power from an engine 1 as a power supply source is transmitted to a variable displacement compressor 4 via a belt 2 and an electromagnetic clutch 3. The capacity of the variable capacity compressor 4 is controlled by a compressor capacity control signal 5 from the outside. The voltage of the electromagnetic clutch 3 is controlled based on a signal from a clutch voltage controller 6 as clutch power adjusting means. A clutch voltage calculation value signal calculated by a microcomputer 7 serving as clutch power calculation means is sent to the clutch voltage controller 6.
[0020]
In this embodiment, the driving force recognizing means for recognizing the driving force of the compressor 4 comprises a thermal load recognizing means for recognizing a thermal load having a correlation with the driving force. In the present embodiment, this heat load is generated by the microcomputer 7 from the compressor capacity control signal 5, the engine speed signal 8, the vehicle speed signal 9, the signal 10 from the outside air temperature sensor, the signal 11 from the solar radiation sensor, and the in-vehicle temperature sensor. Signal 12, air conditioner control mode information signal 13, blower voltage signal 14, cooling fan voltage signal 15, and inside / outside air switching information signal 16, which is calculated as a compressor torque, and based on this, a necessary clutch voltage is calculated and controlled. It has become.
[0021]
FIG. 6 is a flowchart showing an example of control of the apparatus. When the clutch voltage is turned on (step S1), first, the clutch-off time until then is calculated (step S2), and based on this, the value of the clutch voltage maximum value control at the time of starting the compressor is controlled (step S3). ). That is, as shown in FIG. 1, the compressor power is not stabilized for a certain time Δt from the time of starting the compressor, and the value of the compressor torque at the time of starting the compressor becomes large. During this period, the maximum clutch voltage is applied.
[0022]
There is a correlation as shown in FIG. 7 between the clutch voltage to be applied when starting the compressor and the length of time during which the clutch is off. That is, the longer the clutch-off time is, the larger the clutch voltage V at the time of startup is, and the shorter the clutch-off time is, the smaller the compressor torque at the time of startup is, and the clutch voltage may be reduced. Therefore, the clutch maximum voltage (MAX voltage) within Δt time is changed and controlled according to the length of the clutch off time. That is, the clutch maximum voltage as described above is controlled only during the Δt time at the start-up with respect to the clutch voltage required from the thermal load f.
[0023]
Referring to FIG. 6 again, the clutch voltage is controlled to the maximum value at the time of start-up as described above (step S3), and it is determined whether or not the time Δt (seconds) required for the control to stabilize the compressor torque has elapsed. (Step S4). If not, clutch voltage maximum control is continued, and if it has elapsed, a clutch voltage value based on the thermal load is calculated (step S5). As described above, this calculation includes the compressor capacity control signal (EMPCV), the engine speed signal (Es), the vehicle speed signal (Sp), the vehicle interior temperature signal (Tr), the outside air temperature signal (Tam), and the solar radiation signal (Tst). ), Blower voltage signal (BLV), cooling fan voltage signal (CV), inside / outside air switching damper opening signal (α) as an inside / outside air switching signal, and air conditioner control mode (A / C mode) signal (Am). (Step S6) Based on these signals, the clutch voltage value Tn to be controlled is calculated by the following equation.
Tn = f (EMPCV, Es, Sp, Tr, Tam, Tst, BVL, CV, α, Am)
Based on the calculation result, the clutch voltage after the lapse of the Δt time is controlled.
[0024]
For example, as shown in FIG. 8, the clutch voltage (clutch power) is controlled to a required minimum power or a slightly larger value depending on the thermal load at that time than the conventional maximum value constant control. Is done. Therefore, in the dehumidification mode (DRY) or economy mode (ECON), significant power saving can be achieved compared to the conventional control according to the outside air temperature or the like.
[0025]
At this time, as indicated by a broken line (clutch power [control value of the present method]) in FIG. 8, the clutch does not slip even if the compressor power increases due to a change in engine speed during traveling, so that there is a slight margin. It is preferable to control the clutch voltage.
[0026]
FIGS. 9 and 10 show a power transmission control device according to the second embodiment of the present invention. The difference from the first embodiment is that the internal variable compressor 21 is used as a compressor. There is no control signal input. Since other configurations and controls are substantially the same as those in the first embodiment, the same reference numerals as those in the first embodiment are assigned to corresponding portions, and description thereof is omitted. Also in the second embodiment, the maximum voltage at the start-up is controlled based on the clutch voltage characteristic as shown in FIG. 7, and the power saving control as shown in FIG. 8 is performed after the lapse of Δt time.
[0027]
11 and 12 show a power transmission control device according to a third embodiment of the present invention, and shows a case where a torque sensor 31 that directly detects the torque of the compressor 21 is used as a driving force recognition means. . As shown in FIG. 12, the compressor torque (Toruku) is directly input instead of the heat load information (step S7), and thereby the clutch voltage Tn is calculated by the following equation (step S8).
Tn = f (Toruku)
Also in the third embodiment, the maximum voltage at the start-up is controlled based on the clutch voltage characteristic as shown in FIG. 7, and the power saving control as shown in FIG. 8 is performed after the lapse of Δt time.
[0028]
In each of the above embodiments, the clutch maximum voltage control at the time of start-up is performed for Δt time. However, while the driving force recognized by the driving force recognition means immediately after the clutch is turned on is not less than a certain value, the clutch Maximum voltage control may be performed.
[0029]
【The invention's effect】
As described above, according to the power transmission control device of the present invention, the power of the electromagnetic clutch is not a constant value, but the compressor capacity, the rotational speed of the power supply source, the temperature of each part, the amount of solar radiation, the air conditioning control mode, etc. According to the various state quantities, the required power value can be controlled, so that significant power saving can be realized as compared with the conventional method.
[Brief description of the drawings]
FIG. 1 is a characteristic diagram when a compressor is started.
FIG. 2 is a relationship diagram between compressor power and outside air temperature.
FIG. 3 is a control characteristic diagram showing a relationship between an evaporator outlet air temperature and an outside air temperature.
FIG. 4 is a relationship diagram between clutch electric power and outside air temperature.
FIG. 5 is a schematic configuration diagram of a power transmission control device according to a first embodiment of the present invention.
FIG. 6 is a control flow diagram of the apparatus of FIG.
FIG. 7 is a relationship diagram between a clutch-off time and a clutch voltage.
FIG. 8 is a relationship diagram between clutch power to be controlled and outside air temperature.
FIG. 9 is a schematic configuration diagram of a power transmission control device according to a second embodiment of the present invention.
FIG. 10 is a control flow diagram of the apparatus of FIG.
FIG. 11 is a schematic configuration diagram of a power transmission control device according to a third embodiment of the present invention.
FIG. 12 is a control flow diagram of the apparatus of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 2 as power supply source Belt 3 Electromagnetic clutch 4 External variable compressor 5 Compressor capacity control signal 6 Clutch voltage controller 7 as clutch power adjustment means Microcomputer 21 Internal variable compressor 31 Torque sensor as driving force recognition means

Claims (8)

In a power transmission control device including an electromagnetic clutch for controlling mechanical connection between a power supply source and a driven device, and a clutch power supply means, the power supply source is an engine, and the driven device is a vehicle air conditioner. The compressor provided is a driving force recognition means for recognizing the driving force of the driven device or an amount correlated therewith, a clutch power adjustment means for adjusting the clutch power, and a clutch power necessary for transmitting the power. Clutch power calculating means for calculating, and according to the driving force recognized by the driving force recognizing means during power transmission, the clutch power is adjusted by the clutch power adjusting means so as to be the driving force calculated by the clutch power calculating means. with adjusted, the clutch power during compressor startup when the off-time of the electromagnetic clutch is long large, the electromagnetic clutch O As time clutch power during compressor startup when short becomes small, depending on the length of time that has been off the electromagnetic clutch, the power transmission control device, characterized in that to adjust the clutch power during compressor startup . The driving force recognition means comprises thermal load recognition means for recognizing a thermal load having a correlation with the driving torque of the compressor, and the drive calculated by the clutch power calculation means according to the thermal load recognized by the thermal load recognition means so that a force, adjusts the clutch power by the clutch power adjusting means, the power transmission control device according to claim 1. The compressor is a variable displacement compressor, and the heat load is compressor capacity control signal information, engine or compressor speed or / and vehicle speed or / and outside temperature or / and inside temperature or / and inside / outside air intake air switching information. 3. The power transmission control device according to claim 2 , wherein the power transmission control device is estimated with reference to a voltage of a blower that blows air into the vehicle interior and / or a voltage of a refrigerant cooling fan. The driving force recognition means comprises a torque sensor, a power transmission control device according to claim 1. The maximum clutch voltage is applied to the electromagnetic clutch for the time required for the driving force that has risen immediately after the clutch is turned on, or for the drive force recognized by the driving force recognition means to be a certain value or more immediately after the clutch is turned on. supplies, power transmission control device according to any one of claims 1 to 4. The power transmission control device according to any one of claims 1 to 5 , wherein the clutch power adjusting means includes means for adjusting clutch power by adjusting a clutch voltage. The power transmission control device according to any one of claims 1 to 5 , wherein the clutch power adjusting means includes means for adjusting clutch power by pulse width modulation control or duty control of clutch voltage on / off. The power transmission control device according to any one of claims 1 to 7 , further comprising slip detection means for detecting a rotational speed difference between the power supply source and the driven device, wherein the clutch power is increased during a slip.

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